Mayor Thomas Menino today will celebrate the groundbreaking on Phase One of the Ink Block project - a $200 million mixed use development that will total 315 rental units.

Mayor Thomas Menino on Thursday celebrated the groundbreaking of the Ink Block project — a $200 million mixed-use development that will offer rental units.

Ink Block will also include 41 affordable housing units across three buildings, according to a spokeswoman for Menino. The second phase is expected to start later this year and will add more housing units, bringing the total to 475.

The project will be developed in two phases with an estimated completion date of 2016 and create 250-450 construction jobs, as well as 68 permanent jobs.

Today's groundbreaking will begin with demolition of existing structures at the project site, which is located at 300 Harrison Ave. — the former site of the Boston Herald.